Electric switch



June 24, 1941. G, J, MEUER 2,247,247

ELECTRIC SWITCH Filed Oct. '7, 1938 2 Sheets-Sheet 1 .Fume 24, 19M. G.J. MEUER l ELECTRIC SWITCH Filved oct. '7, 1958 2 sheets-sheet 2 Ill:

, Patented JuneZ-l, 1941 UNITED STATES PATENT vOFFICE ELECTRIC SWITCHGeorge J. Mener, Milwaukee, Wis., assignor to Cutler-Hammer, Inc.,Milwaukee, Wis., a corporation of Delaware Application October '1, 1938,Serial No. 233,828

12 Claims.

This invention relates to improvements in electric switches. Theinvention relates more particularly to improvements in toggle operatedsnap switches of the tool-handle type.

A primary object of the invention is to provide a tool-handle snapswitch of substantially dusttight construction.

Another object is to provide novel means affording substantialdust-tightness of tool-handle switches having various different forms ofoperating levers.

Another object is to improve the details of construction and facilitateassembly of the parts of switches of the aforementioned character.

Another object is to provide a switch operating lever having novel meansfor pivotally supporting and guiding the same whereby wobbling orlateral displacement of the lever is substantially prevented.

l Another object is to provide a tool-handle switch of theaforementioned character having combined contact and terminal members ofnovel form whereby peripheral dust-tightness of the molded insulatingbase is insured.

Another object is to provide a switch of the character last mentionedhaving novel means for insuring substantial dust-tightness of theoperating elements of the switch.

Another and more specific object is to provide for utilization of aresilient, rubber-like material for rendering the switches substantiallydust-tight without appreciably modifying the normal operativecharacteristics of the switch mechanism.

Other objects and advantages of the invention will hereinafter appear.

rThe accompanying drawings illustrate certain embodiments of theinvention which will now be described, it being understood that theembodi- `ments illustrated are susceptibleof modification thetool-handle type, said switch having novel' means for mounting the samein a tool-handle or the like, and the same having elements appliedthereto to render the same substantially dust-tight.

Fig. 2 isla sectional view (double-scale) on the line 2 2 oflFig. 1.

Fig. 3 is a sectional View, on the line 3-3 of Fig. l.

Fig. 4 is `a view (normal size), partly in side elevation and invertical section, illustrating a switch generally similar to the switchof Figs, 1 to 3, but having mounting means of modified form appliedthereto.

Fig. 5 is an end* elevation, partly in vertical section on the line 5-5of Fig. 4.

Fig. 6 is a fragmentary vertical sectional view of the pivotalsupporting and guiding means for the toggle lever shown in Figs. 1 to 5.

Fig. 7 is a view (normal size), partly in side elevation and partly invertical section, of a switch having combined contact and terminalmembers of novel form; a novel form of lever attachment to provide atrigger or linger grip; and novel means for rendering the switchmechanism substantially dust-tight.

Fig. 8 is an end elevation, partly in section on the line 8--8 of Fig-7.I

Fig. 9 is a vertical section substantially on the line 9-9 of Fig. 8,parts of the insulating base of the switch being shown in elevation.

Fig. 10 is a side elevation (normal size) of a switch having a modifiedform of operating lever associated therewith, a portion of therubberlike cap being broken away to illustrate the supporting frame forthe lever.

Fig. 11 is a view, partly in end elevation and partly in verticalsection on the line l l-ll of Fig. 10, a fragment of the flush mountingplate being shown in position, and

Fig. 12 is a fragmentary view, partly in elevaprior patents, No.1,889,259, dated Nov. 29, 1932;

No. 1,977,078, dated Oct. 16, 1934; and No. 2,089,- 032, dated Aug. 3,1937; reference being had to said prior patents for a detaileddescription of certain of the switch parts.

Here, as in said prior patents, I provide a molded insulating base,designated in general by the numeral l5, said base having a recess i6(Fig. 2) yopening to the upper surface thereof. Base I5 is provided witha rib whose flat surface il (Fig. 2) is offset upwardly from the bottomwall of recess it. Slidable upon surface Il is a flat punched insulatingplate i8 which carries a pair of like contactors arranged on oppositesides of said rib.V One of said contactors is shown at i9 as comprisinga metal trip'bent to substantially U-shape, whereby the arms thereofareexposed on the upper and lower surfaces of plate I8. Said contactors arerigidly .and permanently secured to plate I8 as by means of rivets, oneof which is shown at 20. A pair of upper and lowerv resilient stationarycontacts 2| and 22 isl positioned on each side of the aforementioned ribwithin recess IB, the respective contacts being secured to ledges oisetdownwardly from the upper surface of base I as by means of acorresponding number of internally threaded eyelet members which providefor bottom wiring of the switch, in the manne-r illustrated in Fig. 4,of my aforementioned Patent No. 2,089,032. Two of the wiring terminalscrews are shown herein at 23 in Fig. 3.

The toggle snap action mechanism for the switch comprises a wire yokemember 24 pivotally supported above base I5 but depending into therecess I6; a toggle operating lever 25 pivotally supported above yoke24; a flat punched insulating plate 26 pivotally supported by said yoke,the lower end of plate 26 projecting into a slot or opening Isa in plateI8 to provide a lost motion driving connection between said plates. Acoiled spring 2l is interposed under compression between the lower endof lever 25 and plate 26, a portion of which telescopes into the lowerend of said spring. Spring 21 carries at its upper end a metal cup 28for engagement 'by said lower end of lever 25.

A at metal plate 29 is superimposed upon the upper surface of base I5,aiiat punched or sheared plate or piece of resilient, rubber-likematerial 30 being interposed between plate 29 and the upper surface ofbase I5. Plates 29 and 30 are provided with alined centrally locatedopenings 29a, 3l)a (Fig. 2) which provide oscillating clearance for yoke24 and the aforementioned parts associated therewith. Superimposed uponplate 23 is a sheet metal top plate the peripheral ange portion of whichis designated by the numeral 3| in Figs. 2 and 3, said top plate havinga centrally located portion 3| of substantially dome-shape. tion 3|a isprovided at its upper end with a relatively narrow opening or slot 3|hextending in a direction longitudinally of base I5, opening 3|b having awidth to rather closely accommodate lever 25 comprising a flat sheetmetal punching, and the length of opening 3|b being such as to provide arather close oscillating clearance for the arc-shaped portions 25bforming an enlargement of said lever. Opening 3|J thus serves to guidelever 25 `for oscillatory movement in a single plane, whereas saidportions 25b of the lever insure substantial closure of said opening 3|bunder all conditions. Y

Dome-shaped portion 3|EL is provided adjacent to the lower end thereofwith alined openings v3|, 3Il (Fig, 3) into one of which an outwardlybent end of one arm of yoke 24 is freely insertable, the bent end of theother arm of said yoke being insertable into the other" opening bytemporarily bending the yoke arms toward each other. Portion 3| isprovided adjacent to the upper end thereof with alined openings 3Ie, 3|fwhich are respectively vertically alined with openings 3|c and 3Id.Openings 3Ie, 3|f are adapted to receive a pin 32 of circular form intransverse cross section, said pin having a head 32a engaging theexterior of one sidewall of porytion 3|a and a hollow shank end 32bwhich is upset over the exterior of the other side wall of said portion3Ia. Pin 32 freely penetrates the Dome-shaped porpassage ofcorresponding circular form in transverse cross section provided in arelatively long metal member 33 to provide a relatively wide area ofbearing engagement between the latter and said pin. Member 33 isprovided at its midlength with a portion 33a of exteriorly polygonalform (preferably square, as best shown in Fig. 2) in transverse crosssection. Lever 25 is provided with an opening 25c to accommodate, with arather close sliding iit, Athe portion 33a, said portion 33a extendingbeyond each side of lever 25, and the material of said portion beingupset against opposite sides of lever 25, as shown at 33D and 33c inFigs. 3 and 6, to rigidly and permanently secure said parts in assembledrelation.

In practice the pin 32 is free to oscillate or rotate within theaforementioned .openings 3Ie, 3| (Fig. 6) but pivotal movement of lever25 is afforded primarily by the bearing engagement of tubular member 33with pin 32. By reason of the rigid connection between lever 25 andmember 33 and the relatively wide area of bearing engagement of thelatter with pin 32 lateral tilting or Wobbling of said lever isprevented. Also as aforedescribed the walls of opening 3|b indome-shaped portion 3|a cooperate with lever 25 to limit the same tooscillatory movement in a single plane. This insures against accidenallateral displacement of the lower end of lever 25 from the cup orabutment 28 at the upper end of spring 21.

Many portable tools (such as grinders, polishers or drills) are usedunder conditions involving the presence of metal dust, stone dust, orother particles in the surrounding air; and if such dust particles haveaccess to the switch chamber they, of course, tend to run the switchmechanism and to greatly reduce the useful life of the latter. It isaccordingly a primary. object of my invention to render the switchchamber substantially dust-tight, and this object is attained in thedevice of Figs. l to 3 by providing a relatively thin walled,dome-shaped insulating member 34 molded from a resilient, rubber-likematerial. Member 34 and the aforementioned plate 30 may be andpreferably are composedY of identical resilient, rubber-like material,a` preferred form of such material being made and sold commerciallyunder the trade-name of Neoprene Such material is extremely live andresilient (or elastic) and is further characterized by its resistance todeterioration under the influence of, or in the presence of, oil orgrease.

As best shown in Figs. 2 and 3 member 34 is provided with a slot oropening 34a which it is to be understood is relatively narrower than thethickness of lever 25 and relatively shorter than the width of theenlarged portion (comprising arcuate portions 25h) of said lever.Therefore the walls of said opening 3l!a will be biased by theresiliency of the rubber-like material into close engagement with thesides and edges of lever 25 in all'positions of the latter, theresiliency or elasticity of member 34 being such as to permit bodilydeformation or distortion thereof as an incident to oscillatory movementof said lever while maintaining said close connection of member 34 withthe latter.

Also as best shown in Figs. 2 and 3 member 34 is provided at its lowerend with a flange portion 34b which overlies the aforementioned topplate 3|, said flange portion 34b being. provided with adownwardly'extending edge portion or peripheral rib 34c which surroundsthe peripheral edge of top plate 3| and engages the aforementioned metalplate 29. superimposed upon flange portion 34b is a metal plate 35having a relatively large centrally located opening- 35a to accommodatesaid dome-shaped member 34. Plate 35 has associated therewith a pair ofnuts here shown as substantially cylindrical elements 36 having threadedpassages 36a extending therethrough. Elements 36 are provided at theirlower ends with reduced portions 36b adapted to extend downwardlythrough correspondingly shaped openings in plate 35, the material ofsaid reduced portions being upset over the lower surface of plate 35, asshown at 36, to rigidly and permanently secure said nuts to said plate.Elements 36 are provided withfurther reduced portions 36d projectingdownwardly through corresponding openings in flange portion 34b andmetal top plate 3| to afford a proper degree of engagement of elements36 with the threaded shanks of a pair of bolts 31 extending upwardlyfrom the bottom surface of base I5.

The fiat upper ends of elements 36 are adapted to abut the inner surfaceof the wall of a cavity provided in a tool-handle or'the like (notshown), said wall having openings formed therein to provide clearancefor the shanks of mounting screws or bolts which take into the upperends of the respective threaded passages 36a. Said cavity wall will ofcourse be provided with a suitable opening to afford oscillatingclearance for the upper end portion of lever 25. As shown in dottedlines in Fig. 2 lever 25 is provided at its upper end with a reducedportion 25d which is adapted for a drive t within a recess provided 'ina spherical knob member 25e. As will be understood, knob 25e is appliedto lever 25 after upward insertion of the latter through thevaforementioned opening 3 lb in portion 3|a of the top plate. The wallsof opening 34"- in the dust-proofing cap 34 are sufliciently elastic topermit downward passage of said cap over knob 25e and the intermediateportion of said lever.

In the modification shown in Figs. 4 and 5 most of the'switch parts areidentical with those aforedescribed and have been given correspondingnumerals of reference. AInstead of the plate 35 and nuts 36aforedescribed, the switch is provided with a plate 38, preferably ofdie cast aluminum,

the opposite'ends of plate 38 extending beyond the respective ends ofbase I5 and having openings 38, 38b to accommodate the Shanks ofsecuring screws (not shown) which take into suitable tapped openings inthe wall of a portable tool housing or handle. Plate 38 is provided witha central opening 38 to accommodate the domeshaped dust-proofing cap 34and the operating lever 39 extending upwardly through the latter, lever39 having a spherical knob 394 attached thereto with a drive lit in themanner aforedescribed.

Formed integrally with plate 38 and extending upwardly at substantiallyright angles thereto adjacent the opposite longitudinally spaced sidesof opening 38c are a pair of transverse ribs 38d and38e, said lugshaving segmental notches or concavities 381, 38g formed in the upper`edges thereof and allned with each other. Notches 38f, 384` provideample clearance to enable thumb operation of lever 39 in eitherdirection, whereas the high portions of ribs 38d, 38 serve to preventaccidental operation of lever 39 or injury thereto in the event of roughor careless usage of the tool to which the switch may be attached. The

switch base I5 and its associa/ted parts are attached to plate 38 as bymeans of a pair of relatively long bolts 49 which penetrate tappedopenings providedin the aforementioned ribs 38d, 38e, the upper ends ofsaid bolts being upset, as shown at 49E, to permanently secure the partsin assembled relation.

'Ihe switches illustrated in Figs. 1 to 6, inclusive, have a ratedcapacity of l0 amperes at 250 volts, whereas the modified form of switchshown in Figs. 7 to 9, inclusive, has a rated capacity of 20 amperes at250 volts. In Figs. 7 to 9, the numeral 4l designates a moldedinsulating base having a recess 42 formed therein and opening to theupper surface thereof. Recess 42 is provided in its bottom wall with anintegral rib upon the flat upper surface 43 of which (Fig. 9) theinsulating plate 44 is sl-idably movable. Plate 44 has attached theretoa pair of bridging contactors, one of which is shown at 45 in Fig. 7.Located within recess 42 are two identical pairs of upper and lowerresilient contacts, one pair of said contacts being shown at 46 and 41in Figs.-

7 and 9. Each contact has rigidly and permanently attached thereto aterminal member 448 (Figs. 7 and 8). Each member 48 comprises an outerend portion 43a providing a flange of square contour; an intermediateportion 48b of cylindrical form; and a reduced inner `end of cylindricalform which penetrates a circular opening provided adjacent to the upperend of its associated contact, and is upset over the latter as shown at48c in Fig. 7 to rigidly unite said parts.

Base 4I is provided at each end thereof with two upwardly openingnotches (preferably of rectangular contour) against the bottom walls ofwhich the respective cylindrical portions 481 of the terminal membersare adapted to seat, as shown at 49 and 50 in Fig. 1. The arrangement issuch that flanges 48a overlap the bottom and side walls of therespective notches and extend to a plane substantially flush with theupper surface of base 4l (Figs. '7 and 8), said flanges being positionedrather closely against the exterior surfaces of the end walls of thebase, whereas the respective contacts are positioned closely against theinner surfaces of said end walls, as shown in Fig. 7; the combinedcontact Y and terminal members being insertable with a and alined withthe aforementioned rib 43 are` barriers 5l and 52 which cooperate withthe respective side walls of recess 42 to assist in retain- `ing theupper and lower contacts of the respective pairs in proper alinementwith each other, while assisting in insulating said pairs of contactsfrom each other. Also formed integrally with the respective end walls ofbase 4| and interposed between the terminal members 48 of the respectivepairs are verti ally extending barriers 53 and 54 (Figs. 8 and toproperly insulate said terminal members and the circuit wires to beattached thereto. Each member 48 is provided with a centrally locatedthreaded passage to accommodate a binding screw 55.

superimposed upon the upper surface of base 4l is a sheet'or plate 56`of the aforementioned resilient, rubber-like material, which overliesthe aforementioned terminal members and screws 55 (Fig. 7) superimposedupon plate 56 is a metal top plate 51, the latter being slightly shorterends 'of the arms of yoke member 65, as shown in to a suitable support.Super-imposed upon 'top plate 61 is a metal plate 58of approximatelydiamond shape, plate 58 having a centrallylocated bulge or dome-shapedportion 58 which is provided with a centrally located circular openingto accommodate the reduced lower end of a hollow metal member or bushing59, said reduced lower end of the bushing being upset over the innersurface of portion 58a, as shown at 59l (Figs. '1 and 8) torigidly'secure said parts in assembled relation.

Pivotally supported within bushing 59, as by means of a pin 68permanently attached thereto, is a lever having a cylindrical upper endportion 6|; a reduced cylindrical portion 6|@ located above pin 68, anda convex lower end 6| which serves as a spring abutment. End 6|b of saidlever engages a concavity or recess formed in the upper end of asubstantially cylindrical metal -member 62, the latter being adapted totelescope into the upper end of a. coiled compression spring 63 (Fig. 9)and having a flange to seat against Kthe upper end coil of said spring.Member |52 is provided in'its lower end with a recess 62a totelescopically accommodate the reduced upper end 64a of a flat punchedinsulating plate 66 which is pivotally supported by the U- shaped wireyoke member 65, the latter being pivotally attached to portion 58a ofplate 58 in the manner illustrated in Figs. 8 and 9. Member 68 isprovided with shoulders which serve as an abutment for the lower end ofspring 63, and the substantially triangular lower end portion of member64 is adapted for cooperation with an opening provided in the contactorYsupporting plate 44 to provide a lost motion driving connection betweenthe former and the latter.

Positioned within recess 42 beneath yoke 65 but above the tips of therespective pairs of contacts is a flat punched insulating plate 66(Figs.

'1 and 9), said plate having' a central slot ory opening 66B (Fig. 9) toprovide oscillating clearance for member 64. Insertable vertically intorecess 42 prior to insertion of the upper contacts (one of which isshown at 46) of the respective pairs is a flat punched insulating plate61 which is interlocked with vertical grooves (not shown) at oppositesides of the aforementioned barrier 5| to prevent lateral displacementof said plate. For practical reasons barrier 52 is provided with likevertical grooves. As b est illustrated in '1, plate 61 is interposedbetween each contactor (45) Iand the upper contact (46) in the oiposiswitch parts in assembled relation. To render the switch chamber(recess 42) substantially dust-tight I provide a molded hollow capmember 69 formed of the aforementioned resilient,

rubber-like material, said cap as shown being preferably inthe form of afrustum of a cone. 'I'he base of cap 69 is provided with an inwardlyextending annular flange which is adapt-ed to closely surround or hugthe aforementioned dome-shaped portion 58a of plate 58, and to underlieand engage with the outwardly projecting Fig; 8, to assist in retainingsaid cap in proper position. The fiat upper end of cap 69 is providedwith a centrally located circular opening of smaller size than the crosssectionalarea of the reduced portion 6| of lever 6I, whereby the wall ofsaid opening closely surrounds or hugs said reduced portion 6|a of thelever. It is to be understood that the material of cap 59 issufficiently elastic or stretchable to permit forcing of theaforementioned opening downwardly over the cylindrical upper end portion6| of said lever after pivotal attachment of the latter to bushing 59 bypin 60. Moreover, the arrangement is such that cap 69 is bodilydeformable to permit the necessary oscillatory movement of reducedportion 6|!a of the lever as an incident to operation of the switch,without destroying the seal or dust-tight grip of the aforementioned Awall of the opening about said portion 6|.

I prefer to attach to lever 6| a finger member or trigger 16, the samepreferably consisting of a die-cast piece of metal such as aluminum.Member 10 is provided with a, recess to accommodate portion 6I of thelever, these parts when assembled as shown being drilled to receive aheaded pin or rivet 18, the shank of which is upset (Fig. 8) to rigidlyand nonrotatably unite said parts to each other. Member 1U is providedwith flat portions 10a and 1|]b adapted to alternatively abut therespective Opposite ends of plate 58, each of said at surfaces havingrecesses, as'shown in Fig. 9 to provide clearance between the same andthe protruding shank ends of bolts 68 and 688. When the switch isprovided with a trigger member 18 it is of course desirable to providefor biasing member 18 to one of its extreme positions. For this purposemember 18 is recessed as shown in Fig. 9 to accommodate a. coiled spring1| which is interposed under a predetermined degree of compressionbetween the inner end of said recess vand the upper surface of plate 58,bolt 68 being made suii'iciently long so that the lower end coils ofspring 1| may be telescoped onto the exposed shank portion to restrainthe spring against lateral displacement. As indicated in Figs. '7 and 9the arrangement is such that the switch will be biased to circuitinterrupting position.

As Will be obvious from Fig. 9 the switch may be modified to provide fornormally biasing the sameV to circuit completing position by merelyattaching member 10 to lever 6| in a position of the former degreesremoved from that illustrated, the positions of bolts 68 and |58a beingreversed rwith respect to base 4| to provide for cooperation of theshank of bolt 68 withspring 1| in the changed location of the latter.

In Figs. 10 to 12, inclusive, I have shown a tool-handleswitch having arated capacity of 6v amperes at 250 volts; it being understood that theswitch mechanism is in many respects quite similar to the switchmechanisms aforedescribed. In Figs. 10 to 12, however, I' provide aspecial form oflactuating lever and a special form of supporting anddust-'proofing elements. Thus, base 12 is provided with an upwardlyopening recess withinwhich the stationary and movable contacts arepositioned, the stationary contacts being provided with suitableend-wiring terminal elements, two of which are shown at 13 in Fig. 11.The exposed portions `of elements 13 extend downwardly from a planesubstantially ush with the'upper surface of base 12, the lower endportions of said elements being provided with tapped openings toaccommodate the shanks of binding screws 14.

Superimposed upon, and being substantially co-extensive with the uppersurface of base 12 is a sheet or plate 15 formed of resilient,rubberlike material of the character aforementioned. A punched andstamped sheet metal top plate 1E of substantially the same width as base12 is superimposed upon sheet 15, a pair of screws or bolts 11 extendingupwardly through base 12 and sheet 15 and taking into tapped openingsprovided in plate 16. Flate 16 is provided with upward extrusions 18aand 16b surrounding said openings, and the threaded shanks of said boltspreferably project upwardly a substantial distance beyond saidextrusions, as shown in Fig. 12. Plate 18 is provided with integralupwardly extending parallel -arms 18c and 16d at opposite ends thereof,and said arms are provided with integral horizontal extensions 18e and16f having tapped openings formed therein to accommodate the shanks ofscrews 18 having countersunk heads to t into openings 19a, 19h, ofcorresponding shape, in a substantially flush relationship to the upperor outer surface of a hollow tool-handle casing or housing, a fragmentof which is shown at 19,

Sheet 15 and plate 16 are provided with alined, centrally locatedopenings (Figs. 11 and 12) which provide oscillating clearance for theupper end of a coiled compression spring 80 and the lever abutment 8laassociated therewith, a sheet metal member 82 being positioned withinthe upper end of spring 8D for engagement by said abutment. Plate 16 hasattached thereto on opposite longitudinal sides of the opening therein apair of upstanding. parallel arms 83 and 84, said arms having integrallugs penetrating corresponding openings in said plate and being upsetover the lower surface of the latter, as indicated in dotted lines at84a and 84b in Fig. 12, and at 85a and 85h in Fig. 10. As bestillustrated in Fig. 11, arms 83 and 84 are provided with alinedopeningsfor pivotal yengagement by the outwardly bent ends of the arms of thewire yoke member 85. Said arms 83 and 84 are providedv punched sheetmetal lever 8l and through the teeter-bar or thumb lever 81, which isrecessed to accommodate the upper end portion of lever 8l. In practicethe thumb lever 81 consists of a die casting composed of `a zinc basemetal, or a similar light weight metal adaptable for formation by diecasting.k As shown in Fig. 11 the shank end 86B of` pin 86 is upset toretain the parts in assembled relation.

Thumb lever 81 is provided with downwardly opening recesses 81a and 81Deither of which is adapted to` 4accommodate the upper end portion of acoiled compression spring 88, the lower end coils of which surround oneof the extrusions 16a or 1lib and the upwardly projecting shank end ofone of the bolts 11. As shown in Fig. 12, spring 88 is interposed undera predetermined degree of compression between the inner end of recess81aand the upper surface of top plate 1B, which it is to be understoodprovides a normal bias of the switch mechanism to circuit interruptingposition; it being obvious that upon transfer of spring 88 to recess 81bthe switch mechanism will be normally biased to circuit completingposition.

Thumb lever 81 is preferably provided with knobs or projections 81, 81dat its opposite ends to facilitate manual tilting thereof to effectoperation of the switch mechanism.

As shown in Figs. 10 and 12 thumb lever 81 is provided with end surfaces81e and 81t of arcuatey contour, said arcuate surfaces extending fromknobs 81c and 81d to the lower surface of said thumb lever. Thisformation of thumb lever 81 is such as to insure a like contour of saidlever in all positions thereof in a plane substantially flush with theouter surface of the housing or plate 19.

In order to insure substantial dust-tightness of the switch mechanism Iprefer to provide a molded hollow cap vmember 89 having a lower portion89E of substantially rectangular contour, the peripheral lower edge ofsaid rectangular portion being adapted to seat against the upper surfaceof top plate 16, as shown in Figs. 11 and 12, said portion 89a being ofa size to accommodate arms 83 yand 84 and the switch parts associatedtherewith, and to provide oscillating clearance for thumb lever 81. Capmember 89 is provided with an upper end portion 89b of a lengthcorresponding to portion 89a (see Fig. 12) but of lesser width than saidportion 89EL (see Fig. 11), said portion 89b being adapted to fit Withinan opening 19c in housing 19 in a substantially flush relationship tothe outer surface of the latter. Member 89 is provided at opposite endsthereof with integral lugs or extensions 8.8

and 89d which are adapted to be clamped between housing 19 and therespective lugs 16e, 16

(Fig, 12), said lugs being notched as indicated in Fig. 12 to provideclearance for the shanks of screws 18.

The inner wall surface of said upper portion 89b is formed at oppositeends thereof to provide -a close sliding fit with the arcuate surfaces81e, 81f on member 81, as best shown in Fig. 12, and the opposite sidesof said inner wall surface are formed to provide a close sliding t withthe respective sides of member 81, as shown in Fig. 11.

) f Said upper portion 89b of member 89 is thus provided with an openingwhich permits oscillation of member 81, whereas the latter is entirelysurrounded and closely engaged by the rubber-like material of member 89to insure substantial dusttightness of the switch as a whole.

What I claim as new and desire to secure by Letters Patent is:

1. In an electric snap switch, in combination, an insulating base havinga reces-s formed therein and opening to the upper surface thereof,stationary switch contacts located within and carried. by the walls ofsaid recess, contactor means also located within said recess, operatingmeans including a pivoted lever projecting from said base, saidoperating means being adapted to effect snap movement of said contactormeans Vinto and out of bridging engagement with said contacts, a metaltop plate secured to said base in sealing relation to the peripheralwall of said recess and having an opening to accommodate the projectingportion of said lever, and yieldable, resilient rubber-like meansoverlying the opening in said top plate and. attached. to the latter andacting by its own resiliency to closelyy tacts located within saidrecess and biased to-l ward each other, means comprising a iiat plateof4 insulating material continuously interposed between said contactsand movable relatively thereto, a contactar carried by said plate andmovable thereby into and out of bridging engagement with said contacts,manual operating means comprising a lever the upper end of whichprojects from said base, spring means interposed between the lower endof said lever and said plate to effect the aforementioned movements ofsaid contacter with a snap action, means comprising a metal top platefor substantially closing and sealing the upper end of -said recess andhaving anA opening providing oscillating clearance for the upper end ofsaid lever, and a hood? formed of resilient, rubber-like materialoverlying said opening and interlocked with said` metal top plate toretain said hood in assembled relation, said hood having a relativelysmall opening formed therein, the wall of said opening being stretchableto accommodate said lever during assembly of said parts and to surroundan intermediate portion of the lever with a close fit in all positionsof the latter, whereby said recess is rendered substantially dust-tight.

3. As an article o f manufacture, a sealing device ior direct attachmentto and support by otherwise complete electric snap switches of thetoggle type, said device comprising a hollow, self-sustainingsubstantially dome-shaped member molded from a resilient, elasticrubber-like material, said member being formed to profvide aself-maintaining resilient interlocking connection between the same andthe metal top plate of a switch, and said member having an openingformed in the upper end thereof, the wall of said opening beingstretchable to accommodate a toggle lever of suitable form and to engageby its own resiliency with a close iit an intermediate portion of thelever, the material of said part around said opening being yieldable toaccommodate the movements of said lever while maintaining said close fitaround the intermediate portion of the latter solely by the elasticityof said material.

4. In a toggle snap switch of the tool-handle type, in combination amolded insulating base having a recess formed therein and opening to theupper surface thereof, a metal top plate superimposed upon said base anddirectly rigidly attached thereto, a resilient, rubber-like gasketinterposed between said top plate and the upper surface of said base toprovide a substantially dust-tight seal for the entire peripheral upperedge of the wall of said recess, said top plate having an upwardlyextending hollow projection, an operating lever pivotally supportedwithin said projectionl and having a portion extending upwardly from thelatter, a relatively thin--walled hollow molded member of resilient,elastic, rubber-like material directly attached to said top plate andextending above said projection, and saidy member having a relativelysmall opening formed in the upper end thereof to forcibly accommodatesaid lever to permit assembly of said parts and to provide a close tabout an intermediate portion of said lever, the material of said memberbeing yieldable to accommodate the movements of said lever whileinsuring selfmaintenance of the close lit aforementioned.

5. A substantially dust-tight snap switch of the tool-handle typecomprising, in combination, a molded insulating base having a recessvformed therein and opening to the upper surface thereof, stationary andmovable switch contact elements positioned within said recess and wiringterminal elements accessible from the exterior of said base, a flatmetal plate superimposed upon said base and a at, rubber-like gasketinterposed between said plate and the upper surface of said base, saidgasket providing a substantially dust-tight seal around the peripheralupper edge of said recess, said plate and said gasket having alinedsubstantially centrally located openings formed therein, a sheet metalmember having a fiat portion seated upon said plate, said member havinga centrally located portion oi substantially dome-shape, said domeshapedportion having a relatively narrow opening formed therein and extendinglongitudinally of said base, a ilat punched sheet metal lever positionedwithin said opening and pivotally supported with respect to saiddome-shaped portion, a yoke member pivotally supported below s-aidlever, a coiled compression spring interposed between said lever andsaid yoke member, means associated with said yoke member for effectingsnap movements of said switch operating elements upon movement of saidlever in opposite directions respectively, a molded hollow cap memberformed of resilient, rubber-like material overlying and engaging saiddome-shaped porti-on, said cap having a relatively small opening formedtherein to forcibly accommodate said lever and to closely engage thesides and edges of said lever in all positions of the latter, said caphaving a peripheral ange, a perforated, flat punched sheet metal plateoverlying said flange, a pair of nuts associated with said lastmentioned plate, and a pair of bolts extending upwardly through saidbase and engaged with said nuts to retain said overlying parts inassembled relation.

6. In an electric switch of the snap action toggle type, in combination,a molded insulating base having a recess opening to the upper surfacethereof, a top plate secured to said base in substantially dust-tightrelation to the peripheral upper edge of the wall of said recess,stationary and movable contacts located within said recess, operatingmeans for said, movable contacts comprising a pivoted lever having aportion thereof projecting upwardly beyond said base through an openingin said top plate and spring toggle snap action means associated withsaid lever at the lower end of the latter, and a hollow molded capmember of substantially dome-shape secured to said top plate andoverlying the opening in the latter, said cap member comprising ayieldable, rubber-like material and the same having a relatively smallopening formed in the upper end thereof to forcibly accommodate 4said*lever when assembled and to hug an intermediate portion of the latter,whereby said cap completes a substantially dust-tight seal for saidrecess and the switch parts located therewithin.

'7. In an electric snap switch of the tool handle type, in combinati-on,a. molded insulating base having a recess formed therein and opening tothe upper surface thereof, a rib formed integrally with the bottom wallof said recess and having a flat surface located above said bottom wall,a pair of upper and lower resilient stationary contacts located on eachside of said rib and respectively biased below and above the plane ofsaid flat surface, a thin, punched insulating plate slidable upon saidflat surface and interposed between the contacts of the respective pairsin all positions of said plate, said insulating member having a pair ofstrip metal contacts attached thereto and exposed upon the upper andlower surface thereof for movement 4thereby into and out of bridgingengagement with said pairs of contacts,.each of said contacts having amachined metal terminal member rigidly attached thereto, said basehaving notches formed in the upper edge thereof to freely accommodatesaid terminal members in a plane substantially flush with the uppersurface of said base, each of said terminal members having a tappedopening extending therethrough in a plane parallel to but offsetdownwardly from the upper surface of said base, binding screws theShanks of which cooperatively engage said tapped openings, a metal topplate overlying the upper surface of said base and secured thereto, aninsulating plate of resilient rubber-like material interposed betweensaid top plate and said base, said insulating plate cooperating withsaid terminal members to retain the latter in assembled position and toprovide a substantially dust-tighty seal around the peripheral upperedge of said recess, said top plate having an opening, `an oscillatableactuating lever positioned within said opening and extending upwardlyfrom said base, and a molded resilient rubber member closely engagingthe upper end portion of said lever and said topplate to alford adust-tight closure for said opening in the latter.

8. In an electric snap switch of the tool-handle type, in combination, amolded insulating base having a recess formed therein and opening to theupper surface-thereof, a rib formed integrally with the bottom wall ofsaid recess and having a at surface located above said bottom wall, apair of upper and lower resilient stationary contacts located on eachside of said rib and respectively biased below and above the plane ofsaid dat surface, a thin, punched insulating plate slidable `upon saidfiat surface and interposed Icap being yieldable to permit oscillatorymovement of said lever while maintaining said close connection with thelatter.

9. In an electric snap switch of the toggle type, a molded insulatingbase having a recess opening to the upper surface thereof, stationaryand movable contact elements locatedA within said recess, anoscillatable operating lever, a

' sheet metal member superimposed upon said between the contacts of therespective pairs in of said terminal members having a tapped openingextending therethrough in a ,plane parallel to but offset downwardlyfrom the upper surface of said base, binding screws the shanks of whichcooperatively engage said tapped openings, a metal top plate overlyingthe upper surface of said base and secured thereto, an insulating plateinterposed between said top plate and s aid base, said insulating platecooperating with said terminal members to retain the latter in assembledposition and to provide a substantially dust-tight seal around theperipheral upper 'edge of said recess, a'lever pivotally supportedrelatively to said top plate and having a portion projecting upwardlyfrom the latter, means providing a toggle snap action connection betweensaid lever and said insulating member. and means comprising adome-shaped cap of resilient. rubberlike material engaged with andattached to said top plate, said cap having a relatively small openingformed in the upper end thereof to forcibly accommodate said lever andto closely surround an intermediate portion of the latter, said base andrigidly attached thereto, said sheet metal member being formed toprovide a clearran'ce opening and a pivotal support for said lever, ayieldable, elastic insulating sheet interposed vbetween said sheet\metal member and shape in vertical cross sections at right angles toeach other and having a peripheral lower edge affording a substantialdust-tight seal around said clearance opening, said hollow member havingan opening formed in the upper end thereof to forcibly accommodate anintermediate portion of said lever, and to provide a substantiallydusttight connection with the latter in all positions thereof, wherebysubstantially complete dusttightness of said recess is insured, andmeans associated with said -sheet metal member for clamping said hollowmember in assembled relation thereto. m

10. In an electric snap switch of the toggle type, in combination, amolded insulating' base having a recess opening to the upper surfacethereof, stationary and movable contact elements located within saidrecess, a yieldable, elastic insulating member superimposed directlyupon said base and adapted to provide a substantially dust-tight sealfor the peripheral upper end of said recess, exteriorly accessiblewiring terminal elements penetrating the walls of said recess in adust-tight relationship and elec- 1 trically connected with thestationary contact elements respectively, said` insulating member havinga.' 'centrally located opening alined with v said base recess, anoperating lever pivotally supported above said base and having aspringtoggle snap action connection with said movable contact elements,a molded hollow member formed of elastic, rubber-like material, saidhollow member having a .peripheral lower edge which is adapted tovprovide a substantially dusttight seal around the opening in saidinsulating member, the upper end of said hollow member having an openingformed therein to provide a frictional, substantially dust-tightconnection betweenthe same and said lever, and means associated withsaid baseto retain said insulating member and said hollow member inassembled relation to said base.

11. In an electric snap switch of the toggle type, incombination, amolded insulating base having a recess opening -to the upper surfacethereof, a plurality of pairs of stationary switch contacts locatedwithin said recess. a movable insulating member positioned within saidrecess. a plurality of contacts carried by said insulating member andmovable thereby into and out of bridging engagement with therespectivefpairs' of contacts, manual operating means ycomprising apivoted lever the upper end ofk which projects from said base, springmeans interposed between the lower end of said lever and said insulatingmember to effect the aforementioned movements of said contactors with asnap action, means carried by said base for substantially dusttightlyclosing the upper end of said recess at the periphery of the latterwhile providing insulating clearance for the upper end of said lever,and a hood formed of resilient rubber-like material having its lower endportion interlocked with said last mentioned means to retain said hoodin assembled relation to said base, said hood having an opening formedtherein to accommodate said lever and to surround an intermediateportion of the same with a close fit in all positions of the latter,whereby said recess is rendered substantially vdust-tight.

12. In an electric snap switch of the toggle type, in combination, amolded insulating base having a recess opening to the upper surfacethereof, a plurality of pairsof stationary contacts located within saidrecess, wiring terminal elements associated with said contacts and eX-posed at the outer surface of said base, a movable insulating memberpositioned within said recess, a plurality of contactors carried by saidinsulating member and movable thereby into and out of bridgingengagement with the respec.

tive pairs of contacts, manual operating means comprising a pivotedlever the upper end of which projects from said base, spring meansinterposed between the lower end of said lever and said insulatingmember to effect the aforementioned movements of said contactors with asnap action,'means including a metal top plate for substantially closingand sealing the upper end of said recess while providing oscillatingclearance for the upper end of said lever, and a hood formedofresilient, elastic rubberllike material interlocked with and supporteddirectly by -said metal top plate to retain said hood in assembledrelation thereto, said hood having a relatively small opening formedtherein, the wall of said opening being stretcliable to forciblyaccommodate said lever to permit assembly of said parts and to surroundan intermediate portion of said lever with a close t in all positions ofthe latter, whereby said upwardly op'ening base recess is renderedsubstantially dust-tight while providing4 for exposure of said wiringterminal elements.

GEORGE J. MEUER.

